Guns4Pennies.com is about to auction off this rifle.
The point of interest is mainly the caliber, 458SOCOM. Several types from 70gr frangibles all the way up to 600gr subsonics are. SBR makes several loads, as does Load-X. 350gr ball load is shown below.
The rifle is nicely made, as seems typical for RRA.
The rifle is the same size and weight as .223 but launches a much bigger payload. Standard “30rd” magazine fits ten shots of .458SOCOM.
Approximate ballistic effect on target is approaching that of a 12ga sabot slug.